Connection coalescing with ORIGIN Frames: fewer DNS queries, fewer connections

What this post added

This post details the research and prototyping of connection coalescing using HTTP/2 ORIGIN Frames. It explains the problem of excessive DNS queries and connections for web page rendering, and how ORIGIN Frames can be used as an explicit signal from servers to clients to enable the reuse of existing TLS connections for different hostnames. The post outlines the two required steps: sending an ORIGIN Frame with an origin-set and ensuring these hostnames are in the TLS certificate's SAN list. It contrasts this with IP-based coalescing and highlights the benefits of reduced latency, improved security by limiting metadata exposure, and simplified management for CDN operators.